PT  - JOURNAL ARTICLE
AU  - Andrew J. Montgomery
AU  - Kris Thielemans
AU  - Mitul A. Mehta
AU  - Federico Turkheimer
AU  - Sanida Mustafovic
AU  - Paul M. Grasby
TI  - Correction of Head Movement on PET Studies: Comparison of Methods
DP  - 2006 Dec 01
TA  - Journal of Nuclear Medicine
PG  - 1936--1944
VI  - 47
IP  - 12
4099  - http://jnm.snmjournals.org/content/47/12/1936.short
4100  - http://jnm.snmjournals.org/content/47/12/1936.full
SO  - J Nucl Med2006 Dec 01; 47
AB  - Head movement presents a continuing problem in PET studies. Head restraint minimizes movement but is unreliable, resulting in the need to develop alternative strategies. These include frame-by-frame (FBF) realignment or use of motion tracking (MT) during the scan to realign PET acquisition data. Here we present a comparative analysis of these 2 methods of motion correction. Methods: Eight volunteers were examined at rest using 11C-raclopride PET with the radioligand administered as a bolus followed by constant infusion to achieve steady state. Binding potential (BP) was estimated using the ratio method during 2 periods of the scan at steady state. Head movement was compensated by using coregistration between frames (FBF) and 3 methods using MT measurements of head position acquired with a commercially available optical tracking system. Results: All methods of realignment improved test–retest reliability and noise characteristics of the raw data, with important consequences for the power to detect small changes in radiotracer binding, and the potential to reduce false-positive and false-negative results. MT methods were superior to FBF realignment using coregistration on some indices. Conclusion: Such methods have considerable potential to improve the reliability of PET data with important implications for the numbers of volunteers required to test hypotheses.